Conventional bicycles typically have pedals that are substantially perpendicular to the bike frame, that is, the pedals are parallel to the knee joint axis. However, many individuals have feet that are not parallel to the knee joint axis, especially when the feet are in the subtalar neutral position.
This situation is especially problematic for individuals with existing pronation and/or supination conditions, wherein significant rearfoot and/or forefoot valgus and/or varus conditions are present. For example, some of these individuals may have “bowed” lower legs (e.g., laterally or medially), and as a result, the supinators and/or the pronators attempt to compensate by maintaining a neutral or level foot posture relative to the bicycle pedal. In these situations, the bicyclist attempts to compensate for the valgus/varus conditions.
Because of these different mechanical conditions being present, the bicyclist's foot needs to maintain constant and consistent medial-lateral even pressure over the pedals, and without this even pressure, the muscles, bones, tendons and ligaments of the bicyclist's foot (as well as other parts of the body) can become stressed and/or injured as the ankle repeatedly rolls, or attempts to roll, either laterally or medially. In these situations, it is difficult for the rider to maintain proper contact and alignment between the soles of their shoes and the pedal surface. As a result, great effort must be made by these individuals to apply the requisite force necessary to propel the bicycle forward, thus making bicycle riding generally unenjoyable and competitive bicycle racing difficult, if not impossible.
A new and improved forefoot wedge for a piece of footwear, e.g., a shoe, such as, but not limited to exercise, therapeutic, or physiological footwear, is described in commonly-owned U.S. patent application Ser. No. 12/760,370, the entire specification of which is expressly incorporated herein by reference. The forefoot wedge can be formed of any formable or moldable material that is substantially firm, yet comfortable, when formed, molded, cured or dried. The formable or moldable material is used to uplift the forefoot area of the wearer's foot to cause the subtalar joint of the wearer to assume and/or maintain a neutral position. By way of a non-limiting example, the vertical leg/foot arrangement is being “shimmed level” to the shoe bottom medially/laterally (as the case may require) in the neutral position (e.g., subtalar neutral) in order to achieve relatively good alignment for the body, e.g., when riding a bicycle.
Conventionally, in order to determine what the overall wedge height or thickness of the forefoot wedge should be, it was first necessary to determine the forefoot varus/valgus angle and the rearfoot varus/valgus angle, and then combine the two angles to geometrically determine the overall wedge height or thickness. With respect to pronators, the respective forefoot/rearfoot measurements will yield two different varus angles; however, it should be appreciated that one of the measurements might yield either a 0 degree angle or a very slight valgus angle (e.g., typically in the rearfoot angle measurement). However, pronators typically yield an overall or total positive varus angle result. With respect to supinators, the respective forefoot/rearfoot measurements will yield two different valgus angles; however, it should be appreciated that one of the measurements might yield either a 0 degree angle or a very slight varus angle (e.g., typically in the rearfoot angle measurement). However, supinators typically yield an overall or total negative valgus angle result.
One method to determine the forefoot valgus angle for a supinator (or suspected supinator), required that the wearer's foot be held in non-weight bearing subtalar neutral position (e.g., by a podiatrist), or as close thereto as possible. An appropriate diagnostic tool, such as but not limited to a goniometer was used to measure the valgus angle formed by the tilt of the bottom of the forefoot relative to the bottom of the heel portion. If the wearer's other foot is also affected, a similar measurement would be done for the other foot.
One method to determine the forefoot varus angle for a pronator (or suspected pronator) required that the wearer's foot be held in non-weight bearing subtalar neutral position (e.g., by a podiatrist), or as close thereto as possible. An appropriate diagnostic tool, such as but not limited to a goniometer was used to measure the varus angle formed by the tilt of the bottom of the forefoot relative to the bottom of the heel portion. If the wearer's other foot is also affected, a similar measurement would be done for the other foot.
One method to determine the rearfoot valgus angle for a supinator (or suspected supinator) required that the wearer's foot be held in non-weight bearing subtalar neutral position (e.g., by a podiatrist) or as close thereto as possible. An appropriate diagnostic tool, such as but not limited to a goniometer was used to measure the valgus angle formed by the intersection of the vertical axis extending downwardly through the lower leg area and the vertical axis extending upwardly through the middle of the heel portion. The intersection of these two axes forms a vertex of the rearfoot valgus angle.
One method to determine the rearfoot varus angle for a pronator (or suspected pronator) required that the wearer's foot be held in non-weight bearing subtalar neutral position (e.g., by a podiatrist), or as close thereto as possible. An appropriate diagnostic tool, such as but not limited to a goniometer was used to measure the varus angle formed by the intersection of the vertical axis extending downwardly through the lower leg area and the vertical axis extending upwardly through the middle of the heel portion. The intersection of these two axes forms a vertex of the rearfoot varus angle.
However, all of these conventional measurements are typically made with reference to the bottom third of the tibia.
One method to determine the total wedge angle, and thus the overall wedge height or thickness of the forefoot wedge, includes combining the forefoot angle (whether it be varus or valgus in nature) with the rearfoot angle (whether it be varus or valgus in nature) according to the following formula: Total Wedge Angle=Forefoot Angle (+varus or −valgus)+Rearfoot Angle (+varus or −valgus).
However, the above-described methodology is rather cumbersome and typically requires the user or, more likely, an assistant such as a podiatrist, to be able to accurately use a goniometer to precisely determine the various varus/valgus angles while simultaneously trying to maintain the wearer's foot in non-weight bearing subtalar neutral position. Accordingly, it would not be unexpected to see significant measurement errors and resulting under-correction or over-correction of the pronation/supination conditions with wedge heights that are either too low or too high.
Therefore, it would be advantageous to provide a new and improved measurement tool for determining the varus and/or valgus angles of a pronating and/or supinating foot when the subtalar joint of the foot is placed and/or maintained in a neutral position.